City of Morgan Hill Water System Master Plan 2017

6.4 MODEL CALIBRATION

Calibration is intended to instill a level of confidence in the pressures and flows that are simulated. Calibration generally consists of comparing model predictions to field measured results and making necessary adjustments.

6.4.1

Calibration Plan and SCADA

In order to calibrate the hydraulic model pressure SCADA data was collected for points throughout the water distribution system, as well as water level data for the City’s storage reservoirs. City staff provided 15-minute pressure data for each groundwater well and booster station as well as 15-minute water level data for the City’s storage reservoirs, for a portion of the month of August 2014. The locations that were included in the calibration for tanks, booster stations, and wells were identified on Figure 6.1 . In addition, pressure loggers were installed throughout the system in an effort to enhance the calibration effort and document system conditions away from the vertical infrastructure. Three pressure loggers were placed at various intersections for a one-week period before moving to new locations. In addition to these three rotating pressure loggers, one pressure loggers was placed at a fixed point for the duration of the pressure logging program. The periods of installation for the pressure loggers are summarized on Table 6.1 , while Figure 6.2 documents the points used in the calibration of the hydraulic model. Calibration can be performed for steady state conditions or for extended period simulations (EPS). In steady state calibration, the model is compared to field monitoring results consisting of a single value, such as a single hydrant test. EPS calibration consists of comparing model predictions to diurnal operational changes in the water system. The calibration process for the hydraulic model was extensive, and involved an iterative process which resulted with satisfactory comparisons between the field measurements and the hydraulic model predictions at each well site and the water tank. The calibration results were graphically summarized for each site and included in Appendix A . 6.4.2 EPS Calibration

Representative extracts from Appendix A are shown on Figure 6.3 for calibration points at Diana Well Number 1 and the Edmundson tank.

6.4.3

Use of the Calibrated Model

The calibrated hydraulic model was used as an established benchmark in the capacity evaluation of the existing water distribution system. The model was also used to identify improvements necessary for mitigating existing system deficiencies and for accommodating future growth. This valuable investment will continue to prove its value to the City as future planning issues or other operational conditions surface. It is recommended that the model be maintained and updated with recent construction to preserve its integrity.

June 2017

6-3

City of Morgan Hill Water System Master Plan